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The chloride penetration resistance of the near-surface concrete cover depth is greatly influenced by the type and extent of curing provided. Very short or ineffective curing regimes result in less cement hydration and a more porous surface due to early evaporation of capillary water. The resultant depth-dependent capillary pore structure results in a depth-dependent resistance to ingress of aggressive fluids, such as chloride solutions. Without reliable performance test methods for pre-qualification and quality assurance, minimum requirements for curing in specifications for concrete structures exposed to chlorides are typically prescriptive. In this paper, a series of modified rate of absorption tests is used to describe and quantify the effect of curing on the chloride penetration resistance of two concretes subjected to four different curing regimes, including accelerated moist curing. The proposed test method can be used to optimize curing for durability performance and allow credit for use of accelerated curing. Key words: curing, precast, performance, evaluation, chloride penetration, sorptivity. Dans la cure de beton, le type et l'etendue de la cure fournie ont un effet important sur la resistance a la penetration des ions de chlorure de l'enrobage pres de la surface. Des regimes de cure tres courts ou inefficaces reduisent l'hydratation du ciment et rendent la surface plus poreuse en raison de l'evaporation precoce de l'eau capillaire. Ainsi, la structure des pores capillaires dependant de la profondeur donne lieu a une resistance a la penetration de fluides agressifs, tels que les solutions de chlorure, en fonction de la profondeur. En l'absence de methodes d'essai de performance fiables pour la prequalification et l'assurance de la qualite, les exigences minimales dans les specifications quant a la cure des structures en beton exposees aux chlorures sont generalement normatives. Dans le present document, une serie d'essais de vitesse d'absorption modifiee est utilisee pour decrire et quantifier l'effet de la cure sur la resistance a la penetration du chlorure dans le cas de deux betons soumis a quatre regimes de cure differents, y compris la cure humide acceleree. La methode d'essai proposee peut etre utilisee pour optimiser la cure afin d'obtenir des performances de durabilite et de valider l'utilisation de la cure acceleree. [Traduit par la Redaction] Mots-cles : cure, prefabrique, performance, evaluation, penetration du chlorure, sorptivite., Introduction The type and length of effective curing (controlling both temperature and moisture) impact on the evolution of the degree of cement hydration and microstructural development of the concrete at [...]

ABSTRACT On Thursday, 16 April 2009, Professor H. Donald. B. Jenkins presented an Exaugural Lecture to a packed audience at the University of Warwick, at a Symposium held to honour [...]

A study to evaluate corrosion rates was conducted using pile foundations abandoned during the reconstruction of I-15 through Salt Lake Valley, Utah. Corrosion rates were measured for 20 piles extracted from five sites after service lives of 34-38 years. Measurements were made of soil index properties, resistivity, pH, cation/anion concentrations, and water table elevation. The critical zone for corrosion was typically located within the groundwater fluctuation zone; but correlations with soil properties were generally poor. Despite low resistivity, average corrosion rates for pile caps in native soil were typically between 2 and 9 [micro]m/year with a maximum of 19 [micro]m/year and did not pose any structural integrity problems. Nevertheless, for abutment piles where chloride concentration was very high, the average pile corrosion rate increased to 13 [micro]m/year within the embankment and the maximum corrosion rate was 48 [micro]m/year in the underlying native soil. Based on data from this and previous studies, equations were developed to predict maximum corrosion loss for piles in nonaggressive soil as a function of time. DOI: 10.1061/(ASCE)1090-0241(2008)134:3(341) CE Database subject headings: Corrosion; Driven piles; Infrastructure; Chlorides; Sulfates; Predictions.

In predicting the chloride diffusivity of concrete as a three-phase material, the morphological characteristics of the three phases, the physical properties of each phase constituent material, and the interactions of the three phases in the concrete matrix should all be taken into account. The present paper attempts to develop an analytical method to achieve this. A three-phase composite sphere model for the concrete matrix is proposed to represent the heterogeneous nature of concrete and a closed form solution for the chloride diffusivity of concrete is derived. After verifying the derived closed form solution with experimental results, the effects of key factors that affect the chloride diffusivity of concrete, namely the chloride diffusivity and thickness of the interfacial transition zone (ITZ), the maximum aggregate diameter, and the aggregate gradation are examined in a quantitative manner. It is found in the paper that the most important factor influencing the chloride diffusivity of concrete is the chloride diffusivity of ITZ. When the aggregate volume fraction is equal to 0.8, the relative chloride diffusivity of concrete to cement paste for a given relative chloride diffusivity of ITZ to cement paste at 10 is almost four times that for a given relative chloride diffusivity of ITZ to cement paste at 2. The second most important factor is the thickness of ITZ. When the aggregate volume fraction is equal to 0.8, the relative chloride diffusivity of concrete to cement paste for a given ITZ thickness at 0.05 mm increases by 76% as compared to that for a given ITZ thickness at 0.02 mm. The least important factors are the maximum aggregate diameter and aggregate gradation. The extent to which they influence the chloride diffusivity of concrete is in the range of 10-55%. The paper concludes that the closed form solution derived here can predict the chloride diffusivity of concrete with reasonable accuracy. DOI: 10.1061/(ASCE)0899-1561(2008)20:3(205) CE Database subject headings: Concrete; Chlorides; Diffusivity; Closed form solutions; Predictions.

Several complexes of fluorine substituted phthallic acid anhydrides with chloride anion are optimized and are found to be more acidic. The dual sigma/pi-binding affinity of title compounds are studied by means of ab initio and molecular interaction potential with polarization calculations and Bader's theory of 'atoms-in-molecules'.

An efficient procedure is described for preparing the 2-alkyl glutaconaldehyde derivatives and the corresponding 3-alkylpyridine and 3-alkylpyridinium salts starting from aldehydes and featuring condensation of aldimine anions with vinamidinium chloride. Alkaline hydrolysis of 2-alkylaminopentadieneimine derivatives has allowed access to potassium salts of 2-alkylglutaconaldehyde.

The analysis of the structural, infrared spectra and electronic properties of the N7, N9-dimethylguaninium chloride is presented and the study of the interaction of one cation with one to four chlorine anions and one chlorine anion with two cations is described.

The biochemical characterization of the reaction of superoxide with a new trityl radical, tricarboxylate derivative of perchlorotriphenylmethyl (PTM-TC) is described. The high sensitivity of detection of PTM-TC and the high rate constant of the reaction could be applied to measure superoxide in biological systems.

An experimental program was carried out to clarify the effect of chloride-induced corrosion on posttensioned concrete (PC) beams under different grout conditions using the electrically accelerated corrosion testing method. A series of accelerated corrosion tests were performed to evaluate the influence of insufficient grout condition on corrosion of sheath and prestressing tendon. The radial pressure surrounding the sheath during the corrosion process was also investigated. After a period of accelerated corrosion, the mechanical behavior of the deteriorated PC beams was clarified through loading tests. Prestressing tendon corrosion and its correlation with beam load-carrying capacity was also investigated. The results of the experiments demonstrate a significant influence of corrosion of sheath and prestressing tendon on load-carrying capacity of PC beams. The width of the corrosion crack in PC beams increases with grout filling level inside the sheath. The presence of water inside the sheath leads to increased rates of corrosion of the sheath and prestressing tendon, resulting in an earlier deterioration in the load-carrying capacity of PC beams. DOI: 10.1061/(ASCE)0899-1561(2008)20:1(85) CE Database subject headings: Corrosion; Grouting; Concrete beams; Pretensioning; Post tensioning.

First-principle calculations are used to investigate the adsorption and reactions of B[Cl.sub.3] and its fragments B[Cl.sub.x] on the Ti[O.sub.2] anatase (101) and rutile (110) surfaces. The results show that the possible absorbates on the Ti[O.sub.2] anatase and rutile surfaces are similar and that the B[Cl.sub.x] dissociative adsorption occurs more easily on rutile surface.

The cyclopentadienyl complexes of mercury produced by the reaction of mercuric chloride and KCp' salts show that their solid states are characterized by polymers formed due to interactions between mercury and chloride.

The time-of-flight secondary ion mass spectrometry and reflection absorption infrared spectroscopy were used to determine the properties of supercooled liquid water and the mechanism of crystallization. The supercooled water is found to contain two phases and undergoes immediate crystallization and dissolution of LiCl.

The adsorption equilibria of methanol from diluted solutions of the alcohol in dichloromethane (the weak solvent of the binary mixture) have been investigated in normal-phase conditions on an hybrid polymeric chiral stationary phase. This was done by analyzing the shapes of nonlinear perturbations of methanol, measured with a refractive index detector from a column in equilibrium with pure dichloromethane. Experiments have been set up to demonstrate the displacement effect, predictable from the adsorption data, by a nonlinear pulse of methanol on a racemic mixture of temazepam injected at trace level. A most used method in fundamental studies of band behavior in chromatography has been used for modeling the system. An extraordinary increase of the apparent column efficiency has been observed due to the displacement phenomenon, with the peak of the second eluted enantiomer noticeably higher and narrower than that of the first eluted component.

Several straightforward nucleophilic displacement reactions are used for an efficient synthesis of a large number of functionalized heteroatom-bridged calix[2]arene[2]triazines compounds on the larger rim in good yields. The resulting compounds are found to contain several amino groups, which makes them form numerous complexes with [Cu.sup.2+] ions, hence producing a chelating interaction effect.

The photochemistry of isomeric methoxyphenyl chlorides and phosphates were analyzed in different solvents and in the presence of benzene and were found to involve the triplet state. Results revealed that a unitary mechanism is proposed for the photochemistry of the three chloroanisoles and of the corresponding phosphates in polar solvents and involves a heterolytic [S.sub.N]1 path.

A series of chloride anion receptors containing two catechol head groups connected through their ortho-positions via a spacer chain is reported. The most effective receptor was found to be one in which the hydrogen-bonding linker (-C[H.sub.2]CONH-) is most distant from the catechol units and could only form a seven-membered intramolecular hydrogen-bonded ring.

The synthesis, crystal structure, and mass spectroscopy characterization of nine-atom deltahedral clusters (Zintl ions) of germanium as well as the syntheses and characterization of alkylated clusters with exo-bonds to primary, secondary and tertiary carbon atoms are presented. The obtained species are the first main group deltahedra clusters that are functionalized with purely organic substituents.

Titanocene monochloride has catalyzed the homocoupling of benzylic halides and benzylic gem-dibromides in order to give the corresponding bibenzyl and stilbenyl systems. The exposure of benzylic bromides to Ti(III) in the presence of aldehydes has given rise to the Barbier-type products.

Several 1,3,5-tricarbonyl derivatives were prepared by reaction of 1,3-bisS9ilyl enol ethers) with acid chlorides under mild conditions. 1,3-bis(silyl enol ethers) were derived form methyl acetoacetate and the use of 1,3-diketone-derived 1,3-bis(silyl enol ethers) resulted in functionalzation of the central carbon atom of the bis (silyl enol ethers).

Hexahydro-1H-isoindolones are obtained from a copper-catalyzed coupling of imines, dienylstannanes and acryloyl chlorides followed by a Diels-Alder reaction. The diversification of the core through Pd-catalyzed cross-coupling has defined a new modular approach to isoindolone combinatorial libraries.

The effects of an ester group as an alkyne substituent on the reactivity of propargylic enynes, which inhibits the Rautenstrauch process, are analyzed. The steric interactions in the transition structure have provided different hyperconjugation interaction energies that have helped in determining the magnitude of the energy barrier for the rate-limiting H-abstraction step.

The genomic organization of luxS of Halobacillus halophilus, its regulation and the cellular function of LuxS in the context of the chloride regulon are discussed. LuxS of Halobacillus halophilus is produced only in the presence of chloride and it might be a central player in the chloride regulon of Halobacillus halophilus.

The deuteron quadrupole coupling constants Cq, asymmetry parameters [eta], and electric field gradient orientation for the imidazolium and primary ammonium groups and for a water of crystallization are determined by a deuterium NMR study at 14 T of a single crystal of L-histidine hydrochloride monohydrate. Density functional cluster calculations give an excellent fit to the imidazolium tensor magnitudes and orientations, when appropriate corrections for vibrational averaging are taken into account.

In-situ scanning tunneling microscopy in combination with in-situ surface X-ray diffraction, with a particular focus on adsorbate and potential dependent surface relaxation phenomena, is used to study the surface structure of Cu(100) modified by chloride and iodide in an electrochemical environment. The findings suggest a predominantly ionic nature of Cl-Cu bond under the given electrochemical conditions and the electrochemical annealing effect is mediated by weakened Cu-Cu bond.

The synthesis and characterization of low-spin (2-methylimidazole)(octaethylporphyrinato)iron(III) chloride (perp-[Fe(OEP)[(2-MeHIm).sub.2]]Cl) is presented. A one-dimension hydrogen-bond is formed between chloride anions and uncoordinated imidazole nitrogen atoms and Mossbauer spectroscopy has verified the low-spin state of the species and confirmed that it is a type I low-spin species with ground state [([d.sub.xy]).sup.2][([d.sub.xz],[d.sub.yz]).sup.3].

The kinetics of the reaction between synthetic Fe-S-based clusters and PhCOCl is presented. The reactions of the cuboidal [[Fe4S4(SR)4].sup.2-] (R = Et or Ph] and [[{MoFe3S4-(SPh)3}2([mu]-SPh)3].sup.3-] are studied.

Electron-transfer series are described for three ferric complexes of the pentadentate ligand 4,8,11-trimethyl-1,4,7,11-tetraazacyclotetradecane-1-acetate ([Me.sub.3]cyclam-acetate) with axial chloride, fluoride and azide ligands. The Fe(II), Fe(III) and Fe(IV) species are studied spectroscopically and their UV vis, Mossbauer, EPR, and IR spectra are presented.

The structure and radial distribution function (RDF) of an accurate ab initio model of aqueous chloride ion is calculated at two high-temperature state points by a two-step procedure. The two advantages of the method are that high-level quantum mechanical methods can be used and the differences between the models and the real world' can be estimated.

Conversion of propargyl alcohols to chloroallenes and arylalkynes using the TiCl4/R3N reagent system was studied. The reaction of certain propargyl alcohols with TiCl4 in the presence of tertiary alkylamines gives the corresponding chloroallenes in 37-58% yields but reaction with the tertiary arylamines gives the corresponding arylalkynes in 68-77% yields.

A study was conducted to elucidate the structures and chemistry that occur on a dry silica gel surface when it is treated with P[Cl.sub.5] and moisture. The occurrence of phosphorous bridging between two adjacent silanols sites is seen and bridging structures based on Si-O-P-O-P-O-Si linkages are also seen.

A femtosecond pump-study of the primary events of nitrosyl chloride (CINO) photochemistry in solution is presented. Following 266 nm photolysis, the resulting evolution in optical density is measured for CINO dissolved in acetonitrile, chloroform, and dichloromethane.

X-ray photoelectron spectroscopy is used to characterize the surface chemistry of atomic layer depositions (ALD) of titanium nitride films using alternate doses of TiCl4 and NH3. In terms of the incorporation of contaminants in the grown films, it is found that chlorine is deposited in small quantities on the surface whereas oxygen is detected all throughout the grown films.

An attempt is made to study the kinetics of the reaction of Br atoms with C[H.sub.2]ClBr with the main objective to provide data for comparison with theory in a wide range of temperatures. The absolute reaction kinetics method of laser flash photolysis coupled with Br atom resonance fluorescence detection and three different relative-rate methods with gas-chromatographic analysis were applied to carry out experiments.

A detailed study on ligand preparation and their applications to the amination reactions of unactivated aryl chlorides and Suzuki-Miyaura coupling reactions of different substrates including ortho-substituted aryl chlorides to form hindered biaryls is discussed. A cache model for the Pd/7i complex shows that the likelihood of a Pd-arene interaction might be a rationale for its high catalytic activity.

A general protocol is developed for selective terminal Heck arylations of unfunctionalized alkyl vinyl ethers by using the P(r-BU)3-releasing salt [(t-Bu3)PH]BF4 as the essential additive. The bulky P(t-BU)3 ligand both enhanced the activity of the palladium catalyst, allowing utilization of sluggish aryl chlorides, and improved the terminal selectivity.

The role of efflux pumps in adaptation of previously characterized isolates of Listeria monocytogenes that are either sensitive or resistant to benzalkonium chloride (BC) and also the role of plasmids in natural resistance of L. monocytogenes to sanitizers are investigated. The analysis has shown that not only the presence of the respective efflux pump genes but also their expression under different conditions should be examined to develop strategies for efficient control of L. monocytogenes.

A systematic study was performed about the solvolysis reaction of substituted benzoyl chlorides in the presence of zwitterionic vesicles of dipalmitoyl phosphatidylcholine (DPPC). For benzoyl chlorides with electron-donating groups, which react predominantly through a dissociative mechanism, which is strongly affected by medium properties, the rate constant decreases as the vesicle concentration increases.

Salts of the C(sub 3nu) symmetric hydronium ion, H3O(super +), are obtained in the weakly basic solvents benzene, dichloromethane and 1,2-dichloroethane. This is made possible by using carborane counterions, since they combine the three required properties of very low basicity, low polarizability and high chemical stability, of a suitable counterion.

The application to the case of AgCl is presented, whose high-pressure polymorphism is investigated experimentally by diamond-anvil-synchrotron X-ray diffraction. The method of constant-pressure enthalpy minimization was used for all phases, by fully relaxing the corresponding crystal structure.

X-ray absorption and X-ray photoelectron spectroscopy are used to study the structure of Ti atoms in NaAlH(sub 4) doped with TiCl(sub 3) or I(sub 13).6THF by the ball milling method. The results suggest that the reversible hydrogen capacity of the structure reduces with the increasing number of cycles and is directly related to the decreasing reaction rate.

A dielectric anisotropy property of a TEGDC (tetraethylene glycol-bis(3-methylimidazolium) dichloride) is investigated as a function of frequency. Variation of dielectric anisotropy with respect to spot frequencies reveals that liquid crystal orientation has an n-type property at low frequencies and as the frequency increases dielectric anisotropy character shifts from negative to positive dielectric anisotropy.

The trans-bis[2-(2-chloroethyl)pyridine]palladium chloride was prepared and structurally characterized by X-ray spectroscopy and computational study. The reaction of the palladium complex with quinuclidine in CH(sub 3)CN, at 25 degree Celsius, leads to competing elimination and displacement reactions with formation of vinylpyridine and chloroethylpyridine in the ratio of 1.5:1.

An investigation is conducted by using density functional calculations to study the reactions between Pd and PDCl2 with cellobiose. PD(II) chloride is shown to promote the polymeric chain cleavage and rising rearrangements, whereas Pd is found to insert in to a C-O bond site in the cyclic carbohydrate moiety with binding energies of -0.2 and -0.5 eV at the Cl'-O5' and the O1-(C-1) bonds, respectively.

Direct iodination of 2,2'-bis(diphenylphosphino)-1-1'-binaphthyl (BINAP) dioxide with iodine monochloride and N-iodosucinimide in the presence of trifluoroacetic acid is discussed. Derivatization at the 5,5'-positions to BINAP does not influence enantioselectivities or yields in rhodium-catalyzed asymmetric 1,4-additions.

A theoretical study of the low-lying singlet and triplet states of CIONO is presented along with calculations of excitation energies and oscillator strengths using multireference configuration interaction. A comparison between the calculated electronic energies related to the two dominant excited states of CIONO and BrONO indicates that the transitions lie about 0.6 eV higher if bromine is replaced by chlorine.

Studies are conducted in Halorhodopsin to evaluate the possibility of replacing the chloride anion with inorganic anions and the photocycle is followed under several conditions. It is revealed that the chloride can be replaced with a formate anion but not with larger organic anions like acetate and the decay rate of the M-like intermediate which is exhibited in a titration-like curve is significantly accelerated at low pH during the photocycle.

Hydroxyl radical reactions of selected chlorinated aromatic phenols (2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol) and chlorinated phenoxyacetic acids [2,4-dichlorophenoxyacetic acid (2,4-D), 2,4-D methyl ester, 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP)] are studied using the radiolysis techniques of pulse radiolysis and gamma radiolysis. It is concluded that radiation chemistry is useful for an ostensible understanding of the role of the hydroxyl radical in (super .)OH-mediated oxidation processes.